Power toothbrushes are well known and widely used home appliances. Generally, increased health consciousness has caused consumers to prefer the efficient and reliable mechanical brush action of such appliances to improve and maintain the good health of their teeth and gums. The working toothbrush element typically is driven through various rotary and/or linear reciprocating strokes for vigorous brushing and cleaning action which far exceeds the efficacy of inaccurate manual toothbrush manipulation. An example of a highly advantageous water-powered toothbrush appliance may be found in our co-pending application Ser. No. 070,689, filed Aug. 29, 1979.
In accordance with the disclosure of the co-pending application, motive power for the toothbrush element is provided by a water-powered, nutating action motor having an orbitally moving output member to drive the toothbrush element through an orbital motion without rotation. The primary working stroke of the brush over the teeth and/or gums is effectively largely unidirectional. During the return motion of the brush, its orbital path tends to retract it away from the teeth and gums, or at least lessen the pressure during the return stroke. This motion provides a brush stroke which approximates the theoretical ideal, in that the primary working stroke can be unidirectional, from the base of the gums, either upward or downward as the case may be, toward the tips of the teeth. Moreover, the device of the copending application is conveniently attachable to a household faucet as a source of driving fluid and affords safe, energy-efficient operation.
It is a primary objective of the present invention to provide an improvement in the basic design of nutating action, powered toothbrush appliances of the type disclosed in our copending application. In accordance with the invention, a unique arrangement of structural components is provided to reduce the overall length and width of the device for ease and comfort of handling by the user while affording reliable, convenient operation. Generally, the toothbrush comprises a hand-held housing which mounts a nutating action, fluid-powered motor. The housing includes a valve control portion arranged in the portion of the housing proximate to the areas thereof engaged by a user's thumb when the device is held by a user for convenient manipulation thereof by the user. The valve-control portion is rotatable relative to the remainder of the housing and rotation thereof activates, through a novel mechanical arrangement, a valve-control rod to open and close the fluid source to the nutating action motor. In accordance with a significant feature of the invention, the valve-control rod is arranged to pass directly through the nutating motor itself to minimize the overall diameter of the handheld housing for easy handling of the toothbrush by the user.
The principle valve-control actuator is advantageously arranged for simple manipulation by the user in a manner which maintains the overall slim configuration of the appliance. In addition, the housing generally tapers gradually from the areas thereof held by the user's hand to the toothbrush. The valve-control portion is flush with the remaining portions of the housing and is positioned in the tapering areas of the housing to facilitate a natural gripping action by the user with the user's thumb lying on the valve-control portion. Moreover, as another feature of the invention, the valve-control portion of the housing may be rotated further after the valve has been opened to actuate a second valve mechanism whereby a portion of the motive fluid is diverted through the toothbrush appliance and out the bristles of the brush to provide a water-massage effect during brushing, if desired. To advantage, all of the various working and structural components of the device of the invention may comprise precision moldings of suitable structural plastic material joined together by adhesive or mechanical means, as deemed appropriate to the circumstances.
For a more complete understanding of the above and other features and advantages of the invention, reference should be made to the following detailed description of a preferred embodiment of the invention and to the accompanying drawings.